We propose to measure the number and distribution of small poly(A)-containing RNA sequences present in the mature oocyte of the South African Clawed Toad, Xenopus laevis. In particular, we plan to investigate the degree to which these sequences share sequence homology with the large poly(A)-containing RNA. We also plan to determine whether these sequences are present in somatic cells, whether they are present in other organisms, the degree to which they are translated, and what role, if any, they play in the increase in protein synthesis and in the adenylation process after fertilization, we plan to continue to investigate the large amount of sequence complexity present in tadpole polysomes. The large value of about 100,000 genes is striking and will be pursued. BIBLIOGRAPHIC REFERENCES: M. Rosbash, M.S. Campo and K.S. Gummerson. 1975. Conservation of cytoplasmic poly(A)-containing RNA in mouse and rat. Nature 258, 682-686.